Lai da Curnera, reservoir in Tujetsch, Grisons, Switzerland

Lai da Curnera is a reservoir in the Val Curnera in the municipality of Tujetsch, Grisons, held behind a barrier at the far end of a narrow valley. Its surface covers 81 hectares and holds 41.1 million cubic metres of water. The Rein da Curnera feeds it, and the Vorderrhein passes about 2 kilometres north of the barrier.

Lai da Curnera is a reservoir of the Rein da Curnera in the municipality of Tujetsch, Grisons, impounding 41.1 million cubic metres over 81 hectares. It forms one water-management system with the Lai da Sontga Maria and Lai da Nalps in neighbouring valleys, linked by pipes. All surrounding streams are diverted into it, including the Rein da Tuma from the Tomasee, regarded as the source of the Rhine.

The reservoir's name comes from Val Curnera, the valley it occupies in the municipality of Tujetsch. The signposted Senda Sursilvana trekking route runs along the young Rhine about two kilometres north of the barrier, and walkers on it can pick out the dam wall from the trail. The barrier also appears in the 2014 film Edge of Tomorrow as the supposed alien hideout.

The reservoir lies about 2.5 km south of Tschamut. From the Oberalp Pass road, a small mountain road branches off at the hamlet of Surpalits toward Lai da Curnera; it is closed to traffic and a barrier blocks unauthorised entry, so the dam is reached on foot. The barrier of the lake can be seen from the signposted Senda Sursilvana trekking route along the young Rhine.

The reservoir is part of a single water-management system with Lai da Sontga Maria and Lai da Nalps in neighbouring valleys, joined by pipes. All surrounding rivers are diverted into it, including the Rein da Tuma from Lai da Tuma (Tomasee), known as the source of the Rhine. In the 2014 film Edge of Tomorrow the dam serves as an alleged alien hideout.